Slide-valve.



No. 663,300. Patented Dec. 4, |900.

C F HIGBY SLIDE VALVE. (Application med bec. s, 1899.)

(No Model.)

5M vanto@ @Minuut -ot construction and in the combinationand faces inclined complementary to the converg- FFICE.

Artnr CLARK F. RIGBY, OF MANNINGTON, WEST VIRGINIA.

SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 663,300, dated December 4, 1900.

Application iiled December 8, 1899.

To @llink/0m, 'zit may concern.'

Beit known that I, CLARK F. RIGBY, a citizen of the United States, residing at Mannington, in the county of Marion and State of Vest Virginia, have invented new and useful Improvements in Slide-Valves, of which the following is a specification.

This invention relates to a double-balanced slide-valve, and has for its object to provide a valve which will automatically expand and contract with its seats and remain constantly tight thereon without sticking.

The invention consists in the novel features arrangement of parts hereinafter fully described and claimed, and illustrated by the accom panying drawings, in which- Figure l isa vertical longitudinal sectional view of an engine-cylinder and steam-chest provided with my improvement. Fig. 2 is a sectional plan view on line 2 2 of Fig. l, and Fig. 3 is a vertical cross-section on line 3 3 of the same figure.

lis the cylinder, 2 the steam-chest, and 3 the downwardly-converging valve-seats formed by the inner faces ofthe sides of chest 2. Arranged centrally in each Valve-seat is an eX- haust-port a and on either side of said exhaustport a port 5, the latter leading to opposite ends of the cylinder.

The valve consists of two longitudinal members 6 and 7, having their outer longitudinal ing seats 3, with which they maintain a close iit. The valve members are .recessed on their inner sides to form cavity 8 and are formed adjacent their ends with vertical interlocking tongues 6 and 7, respectively. Arranged in cavity S and bearing on the opposite faces of the valve members are expansible springs 9, which hold the valve members constantly to their seats. The interlocking tongues 6 and 7 hold the members in proper relative position and balance them one against the other in such manner as to prevent excessive steampressure from binding them to the seats. l0 is the link connecting the valve and valvegear. On the outer face of each valve member is depression 1l for covering the cylinderports 5 alternately with exhaust-port 4:.

In practice the valve is made with its members tightly interlocking and without the Serial No. 739.614. KNO model.)

transverse play indicated in the drawings. It is then fitted tightly in operative position between the previously-heated valve-seats, and the latter, being heated, are expanded, as in actual practice. After being thus fitted the valveis removed and edges orfacesl2 and 13 of valve member 6 and tongues 6 are planed off, so that when the steam-chest and valve-seats contract, as when cooling, the valve will cont-ract therewith against the pressure of springs 9, the latter tending all the while to hold the valve members to their seats. As the ports on opposite sides of the valve are of the same area,as are also the ports of the opposite valveseats,steampressure on the valve is equalized. The valve members are in interlocking engagement from top to bottom of the valve, and hence it is impossible for the Valve to twist or become distorted transversely as the result of unequal steam-pressure on its upper and lower portions. Such unequal pressure would occur if the steam-ports were above or` below the vertical center of the valve or if the ports were of irregular form-as, for instance, larger at the top than at the bottomlin which case there would be greater pressure on the upper than on the lower portion of the valve, and the effect of such inequality of pressure or lack of balance would be to cause theinterlocked tongues to bind each other, and thereby defeat the adjustment for which they are provided, and also would cause the valve to wear unevenly, faster at the top than at the bottom, or vice versa.

A slide-valve constructed as here shown and described is always tightly fitted to the seats and responds to contraction and expansion of the latter without sticking.

Having thus fully described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. In a slide-valve, the combination of 0pposite valve-seats, a longitudinally-divided valve operative between and on the seats, one of the valve-sections being formed on its inner face with the inturned tongues 7 eX- tending vertically from top to bottom of the valve, and the other valve section formed with the outwardly-turned tongues 6 extending vertically from top to bottom of the valve, said tongues 7 and 6 interlocking to limit the expansion of the valve uniformly from top IOO dinally divided valve operative between and on the seats, the valve being formed between its ends with an internal cavity, springs conned in the cavity and pressing outward on the valve members, and vertical interlocking tongues on the inner faces of the valve members adjacent their ends, substantially as shown and described.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

CLARK F. RIGBY.

Witnesses:

F. H. WEIBLE, A. A. J. GASKILL. 

